1. Field of the Invention
The present invention relates to an imaging apparatus preferably used to produce a panoramic synthetic image, a control method for the imaging apparatus, and a computer program product for providing a control program for the imaging device.
2. Description of the Related Art
Conventionally, imaging apparatuses have an optical axis displacement mechanism incorporated in an imaging means and thus exert a vibration proofing ability. Herein, the optical axis displacement mechanism can electrically or optically displace an optical center determining the center of a picked-up image. Owing to the optical axis displacement mechanism, the optical center is displaced in order to correct a hand tremble or the like.
In the imaging apparatus, a correlation value indicating a correlation between an image being picked up and an immediately preceding image is detected, and a displacement of a reference optical axis of an optical system is inferred from the detected correlation value. The optical center of the optical system is then displaced in a direction in which the inferred displacement of the reference optical axis is canceled. A hand tremble is corrected by thus displacing the optical center.
In recent years, lots of techniques have been proposed for synthesizing a plurality of images, which are defined with angles of view that are mutually adjacent angles, to produce a panoramic image, and put to practical use. One of the panoramic image synthesizing techniques is such that a plurality of picked-up images is joined while being overlapped. According to the technique, an image to be joined to one image is requested to be defined with an angle of view that is an adjacent angle of the angle of view defining the one image. If the images constituting a panoramic synthetic image are picked up using, for example, a pan head whose position can be controlled highly precisely, a high-precision panoramic image can be produced.
Assume that a plurality of images defined with angles of view that are mutually adjacent angles are picked up with the foregoing imaging apparatus having the vibration proofing ability held by the hands. In this case, first, a reference picture size is designated, and photography is carried out with reference to the reference picture size. If a hand tremble or the like occurs during photography, displacement of the optical axis of an optical system is suppressed owing to the vibration proofing ability. Consequently, deflection of an image caused by the hand tremble is suppressed.
However, the displacement of the optical axis is controlled based on the correlation value indicating the correlation between the image being picked up and the immediately preceding image. It is therefore impossible to suppress a shift of an angle of view, which defines an image and is an adjacent angle of an angle of view defining a reference image, caused by a hand tremble.
Accordingly, one aspect of the present invention to provide an imaging apparatus, a control method adaptable to the imaging apparatus, and a computer program product for providing a control program for the imaging apparatus. Herein, a deflection correction unit that corrects a deflection of an object image by displacing the object image is actuated based on a correlation between first and second object images, which are picked up by an imaging unit, in order to join the first and second object images to form a continuous image.
The deflection correction unit for correcting a vibration of an object image derived from a hand tremble or the like is used to highly precisely achieve panoramic photography, in which a plurality of joinable object images are picked up, with the imaging apparatus held by the hands.
Further aspects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings).